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Extending Diablo Canyon Nuclear Plant would help California meet its climate goals, new study finds

Extending the life of the Diablo Canyon Nuclear Power Plant has the potential to help California meet the increasing challenges of climate change by providing clean, safe and reliable electricity, water and hydrogen fuel for Californians, according to a new study by researchers at Stanford University's Precourt Institute for Energy and the Massachusetts Institute for Technology (MIT) Center for Advanced Nuclear Energy Systems. 

A report cover with a picture of the plant and text reading "An Assessment of the Diablo Canyon Nuclear Plant for Zero-Carbon Electricity, Desalination, and Hydrogen Production

Researchers found that accelerated effects of climate change, along with California’s adoption of ambitious new emission reduction targets since the 2018 decision to decommission the plant will require an unprecedented effort to secure enough clean energy to power the world’s fifth largest economy. Extending the plant’s operation can propel the state forward in achieving its aggressive climate and clean energy goals while protecting ratepayer costs. 

“Since the decision to shutter Diablo Canyon, California has experienced extreme weather, blackouts and record drought,” said Ejeong Baik, co-author of the study and PhD candidate in the Department of Energy Resources Engineering at Stanford. “We hope that an objective look at Diablo Canyon’s potential will spur a conversation on California’s largest source of carbon-free electricity at this critical time.”

A 10-year extension in Diablo Canyon’s operations would reduce carbon emissions from California’s power sector by more than 10 percent annually from 2017 levels, reduce reliance on natural gas and save ratepayers a total of $2.6 billion. Operating the plant until 2045 could save ratepayers up to $21 billion. 

“The worsening climate crisis requires urgent action to accelerate emission reductions,” said lead author Jacopo Buongiorno, director of the MIT Center for Advanced Nuclear Energy Systems. “An inclusive strategy that utilizes Diablo Canyon, in addition to an aggressive build-out of renewables and other sources of clean generation, would significantly reduce California’s power sector emissions over the course of the next two decades.”

Diablo Canyon currently provides eight percent of California’s in-state electricity production and 15 percent of its carbon-free electricity. In January 2018, the California Public Utilities Commission approved a multiparty settlement to shut down the Diablo Canyon nuclear power plant when the current federal license period for the plant’s second unit expires in 2025. However, the licensing process could be restarted by Spring 2023, allowing the plant to operate while a license extension is considered.

The study also found that Diablo Canyon could be enhanced for additional uses beyond electricity. Separate options for the plant could produce emission-free desalinated water and hydrogen. 

Diablo Canyon could serve as a powerful driver of low-cost desalination to serve fresh water to urban, industrial and agricultural users. The site could operate a desalination plant equal in size to the state's largest desalination plant in Carlsbad – or much larger – at about half the cost per gallon of freshwater produced.

As California’s transportation sector transitions from fossil fuels, the state will likely need hundreds of millions of kilograms of hydrogen-based, zero-carbon fuels annually. Diablo Canyon could produce 110 million kilograms of hydrogen annually at about half the cost of hydrogen produced from other clean energy sources.

The full study, An Assessment of the Diablo Canyon Nuclear Plant for Zero-Carbon Electricity, Desalination, and Hydrogen Production, is available for download here.

The study was funded by the MIT Center for Energy & Environmental Policy Research, the MIT Abdul Latif Jameel Water & Food Systems Lab, the MIT Center for Advanced Nuclear Energy Systems, the Rothrock Family Fund, the Pritzker Innovation Fund, The Rodel Foundation, Ross Koningstein, and Zachary Bogue & Matt Ocko.

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